This proposal requests partial support for an international symposium to be convened at the University of Rochester School of Medicine, Rochester, New York, September 2-5, 1980. This symposium will be the Fourth Brain-Endocrine Interaction Symposium and the theme will focus on "Neuropeptides: Development and Aging." The objectives of this symposium are to bring together a selected group of scientists in a forum open to the general scientific population and there discuss the functional-structural correlates of aging phenomena in the central nervous system. Both what is known and what are regarded as major gaps in our knowledge of neuronal aging mechanisms will be identified, discussed, and coupled with what new approaches need to be employed, will all be rapidly published in the proceedings.